The Center for Clinical Epidemiology and Biostatistics (CCEB), the Renal-Electrolyte and Hypertension (REH) Division of the Department of Medicine, and the Division of Nephrology of the Department of Pediatrics (DNP), all within the Perelman School of Medicine (PSOM) of the University of Pennsylvania (Penn), propose to continue and enhance an innovative, rigorous, and highly successful two- to three-year research training pro- gram for in renal epidemiology. This training program attracts trainees from across the US and its graduates are placed in academic institutions nationwide, resulting in a program of high impact. The training program consists of required courses in epidemiology, clinical research methods, biostatistics, and renal epidemiology; elective courses relevant to the trainees' methodological interests; journal clubs and clinical research conferences conducted by participating faculty; extensive independent readings; instruction in the responsible conduct of research; a professional development series; grant writing and grant development experiences; an apprenticeship experience with an experienced investigator; and the completion of an inde- pendent research project in renal clinical research. Two training pathways are included. Pathway One is for nephrologists and other selected physicians without formal prior research training. Pathway Two is for PhD- trained scientists who desire advanced epidemiology training focusing on applying epidemiologic methods to kidney disease. The program: 1) trains scientists to be rigorous and independent investigators able to use a broad array of epidemiological methods to address research issues in nephrology related to the etiology, prognosis, prevention, early detection, treatment, clinical economics, technology assessment, medical decision making, and quality of patient care; 2) provides closely mentored research experiences with faculty preceptors in clinical epidemiology and nephrology; and 3) strengthens the links between traditional epidemiology and nephrology. Most trainees matriculate in the Master of Science in Clinical Epidemiology (MSCE) program. Program strengths are: 1) the history of successful research and training in the CCEB and in the adult and pediatric divisions of nephrology; 2) the collaborative links that already have been forged among the three pro- grams; 3) the comprehensive course offerings and research programs that are available to trainees; 4) the availability of a number of population-based data resources very well-suited for clinical renal research; and 5) an extensive set of experienced and multidisciplinary faculty with successful training records. Also, numerous large data- bases that can be used for research projects and training, a broad array of specialized analytical capabilities available for clinical studies employing methods of clinical epidemiology (e.g., clinical trials, case-control studies, cohort studies, etc.), and commitment of faculty to collaborative research and training, combine to provide an ideal environment for this training program. Finally, Penn and the PSOM promote an academic environment in which basic and clinical research are encouraged and viewed as attractive career paths for physicians.